Per NEC Article 392 and Article 336, tray cables can run openly in listed cable trays, well supported and protected from excessive damage. Cable trays allow easy access for maintenance, which is one of their greatest advantages over conduit. Conduit, on the other hand, is a rigid or flexible tube that provides additional mechanical protection and environmental. The cable trays are open, and this helps wires to cool because of the circulation of air around them. Conduits are enclosed pipes that trap the heat. When the electricity travels through a wire, this wire becomes hot. Tray-rated power and control cables simplify NEC compliance.
